AJP Clutch Master Cylinder Assembly Dot 4 / 5.1, 9.5mm piston, M10 x 1mm 90deg banjo to hose connection.
Sherco Style
AJP part number 650.00.302, 650.00.312C
This is the Sherco specific master cylinder, that has the special lever to reduce the lever ratio and make the clutch slower acting and easier to pull than if you used a standard AJP lever.